The invention relates to improvements in flywheel assemblies for use between the output shafts of combustion engines and the input shafts of variable-speed transmissions for motor vehicles. More particularly, the invention relates to improvements in flywheel assemblies of the type wherein a first flywheel can be connected with the engine, a second flywheel is connectable with the transmission (preferably in response to engagement of a friction clutch), and the flywheels can rotate relative to each other by overcoming the opposition of damper means which become active when the magnitude of transmitted torque fluctuates.
It is already known to equip flywheel assemblies of the above outlined character with damper means having a first damper which operates substantially unassistedly to offer a relatively small resistance to rotation of the flywheels relative to each other in at least one direction from starting or neutral positions, and a second damper which offers a greater resistance to a following stage of angular movement of the flywheels from such neutral positions. In heretofore known flywheel assemblies of the just outlined character, the energy storing elements (such as coil springs) of the first damper alternate with the energy storing elements (such as coil springs) of the second damper in the circumferential direction of the flywheels. Moreover, the energy storing elements of the first damper are disposed at the same radial distance from the axes of the flywheels as the energy storing elements of the second damper. This entails a reduction of the maximum extent of angular movability of the one and/or the other flywheel from the neutral position against the opposition of the energy storing elements of the second damper, i.e., of that damper which is designed to resist rotation of the flywheels relative to each other with a rather large force during the second stage of angular movement from neutral positions. On the other hand, it is often desirable to ensure that the two flywheels be capable of turning relative to each other through a rather large angle against the resistance of one or more relatively strong coil springs or other suitable energy storing elements.